1. Field of the Invention
This invention relates to a golf practice apparatus having a slopable platform, more particularly to a golf practice apparatus having a slopable platform with which variable sloping of the platform can be attained like that of an actual outdoor golf course.
2. Prior Art
Generally, a golf shot is classified into wood or Tee-shot, iron-shot, and putting. Tee-shot is a long distance shot, in which a golfer hits a ball put on a tee pushed into mild flat ground. Iron-shot is a middle distance shot, in which golfer hits the ball settled on the ground toward a green. Putting occurs when that golfer hits the ball on the green to a hole.
There are various hazards, e.g., a pond, woods, and a steep hill, to hamper the shot of the golfer. In most cases, golfer wants to practice at the steepest slope resulting a disadvantageous standing position. To satisfy the needs of a golfer, a golf practice apparatus which exhibits various slope angles to a ground is introduced, which can be installed both outdoors and indoors.
The typical conventional golf practice apparatus is shown in FIGS. 1, 2, and 3. The golf practice apparatus comprises a platform 10, a central tilting member 15 provided under a central portion of a lower surface of the platform 10, and a pair of driving members (FIG. 3) provided in a base member 20 in longitude and traverse for applying a driving force to the platform 10, thereby enabling the platform 10 to be tilted in a predetermined angle around the central tilting member 15.
A ball receiving member 25 is assembled on the lower central portion of the platform 10 for allowing a pivot of a ball of the central tilting member 15. The central tilting member 15 has a ball 15B being pivotedly engaged in the ball receiving member 25, and a shaft 15S extended downwardly from the ball 15B. A lower portion of the shaft 15S is fixed to a central tilting member supporter 16. As shown in FIG. 3, a pair of driving members comprise a pair of screws 30a,30b which are arranged on the base member 20 with crossing at the central tilting member 15, two pair of drum type moving members 35a, 35b, 35c, 35d which are threaded with corresponding screw 30a, 30b, respectively, and can reciprocatedly move along the screw 30a, 30b during the rotation of the screws 30a, 30b. The rotation of each screw 30a, 30b can be attained by mesh engagement between a driving gear 45a, 45b provided at a motor 40a, 40b and a driven gear 50a, 50b provided at one end of each of the screws 50a, 50b. One end of each of the links 55a, 55b, 55c, 55d is hingedly assembled with each of the moving members 35a, 35b, 35c, 35d, and another end of each of links 55a, 55b, 55c, 55d is ball-joined to the lower surface of the platform 10.
Hereafter, the operation of the conventional golf practice apparatus will be described as below.
Firstly, power is applied to the motor 40a, 40b, to enable the driving gear 45a, 45b to be rotated clockwise or counterclockwise. Thus, the driving force of each driving gear 45a, 45b is transferred to each driven gear 50a, 50b meshed with corresponding driving gear 45a, 45b. The screw 30a, 30b is rotated clockwise or counterclockwise by the corresponding rotation of the driven gear 50a, 50b, thus enabling the moving member 35a, 35b, 35c, 35d to be reciprocated along the screw 30a, 30b. Both ends of each of the links 55a, 55b, 55c, 55d are moved as the center at each connecting portion at which each upper end of each of the links 55a, 55b, 55c, 55d is assembled with the platform 10, while each lower end thereof is assembled with the moving member 35a, 35b, 35c, 35d. Each link 55a, 55b, 55c, 55d is placed parallel or perpendicular to the ground. The movement of the links 55a, 55b, 55c, 55d causes a corresponding corner of the platform 10 to move up or down, thereby enabling the platform 10 to be sloped in various angles.
Therefore, the golfer stands on the platform 10 which is sloped according to golfer's need for practicing a shot.
However, in the conventional golf practice apparatus which exhibits various slopes of the platform by the link, if a length of the link is short, the slope angle of the platform is lessened, and a disadvantage occurs since a steep slope can hardly be attained.
Further, in the conventional golf practice apparatus which has a weak supporting structure, each link 55a, 55b, 55c, 55d primarily receives weight of both the platform 10 and golfer, and thus there is a high possibility of an accident because the link can not bear a very high load of the golfer.